The function keys are very useful keys to be able to customise for users, therefore I would like to request them to be customisable. For instance, the function keys could be used together with modifier keys to expand the number of hotkeyable commands.
For instance F2, F3 and F4 are used to toggle solid shading, wireframe and disable egdge display in 3ds Max. One could opt to set curvature combs to Ctrl + F1, etc. Very useful and timesaving stuff, especially to custumise Inventor to be in-line with other software as well.